Arthur e



(No Model.)

A. BLAPPLEYARD. ELECTRICAL HEATING APPARATUS. No. 467,075.. Patented Jan. 12, 1892.

UNITED STATES PATENT OFFICE.

ARTHUR E. APPLEYARD, OF BOSTON, ASSIGNOR TO H. L. MILIJIS, TRUSTEE,

OF MILLIS, MASSACHUSETTS. l

ELECTRICAL HEATING APPARATUS.

SPECIFICATION forming part of' Letters Patent No. 467,075, dated January 12, 1892.

Application filed January 16, 1891. Serial No. 378.006, (No model.)

To @ZZ whom, it may concern:

Beit known that I, ARTHUR E. APPLEYARD, of Boston, in the countyof Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Electrical Heating Apparatus, of which the following is a specification.

This invention has for its object to provide improved means for utilizing an electric cur- 1o rent for heating purposes, and particularly for heating' soldering-irons; and it consists in the improved apparatus, which I will now proceed to describe and claim.

In the Vaccompanying drawings, forming a part of this specification, Figure 1 represents a side elevation of a soldering-iron embodying my invention. Fig. 2 represents a section on line?! 2 of Fig. 1. Fig. 3 represents a section on line 3 3 of Fig. l. Fig. 4 represents a zo side view of a fiat-iron, and Fig. 5 a top view of a heating radiator provided with my improved apparatus.

The same letters of reference indicate the same parts in all the figures.

2 5 In the drawings, ct represents the external shell to be heated, the same being in this instance formed externally like an ordinary soldering-tool and made of copper or other suitable material, although it may be of any 3o other suit-able form and construction. The shell a has a cavity a', in which is fitted a metallic holder or casing l), preferably of cylindrical form, the cavity d being also cylindrical and closely fitting said holder, as shown in Fig. 3. v

c represents a block or mass of any suitable refractory heat-conducting material which is not a conductor of electricity. I prefer to make said block or mass of slate or soapstone,

4o but may make it of any other suitable material. The refractory block c is formed externally to closely fit the interior of the holder b, and is provided with a longitudinal pocket or cavity c for the reception Vof an electrical resistance d, the latter beinga rod or pencil of any material which, although a conductor of electricity, possesses sufficient resistance to cause it to be heated to incandescence by the passage of an electric current through it, so

5o that itv will be caused to heat the block c and the inclosing shell or casing a. I prefer as the material for the resistance d some form of carbon, and particularly a form containing a considerable proportion of graphite or plumbago, the resistance being preferably a rod or pencil of compressed plumbago molded or otherwise formed to fit the cavity or pocket c in the refractory block c. The refractory heat-conducting block c is of rigid or intlexil ble material, such as soapstone or slate, as 6o above referred to, and is therefore capablel of holding the resistance d in its pocket without danger of breakingit,whether the said block is contained in the casing or removed from it. Furthermore, the said block is capable of having the plates e3 and h firmly clamped to its ends without compression of the block.

Electrical connections are made with theresistance d by means i of wires e e', extending through the handle f, the Wire e being con- 7o nected with one endv of the resistance through a screw g, inserted in a metallic plate 7L in one end of the block'c and bearing on one end of the resistance d, while the wire e is connected with a small rod or Wire e2, extending through the block c and electrically connected with the outer end of the resistance d through a metallic plate e3, inserted in the block c, and a screw e4, engaged with said plate and bearing on the outer end of the resistance. The 8o scivews g and e4 should be insulated from all adjoining parts of the apparatus, excepting the resistance and the Wires c and e', so that the course of the current will be through wire e, screw c, resistance d, screw e4, plate e3, rod e2, and wire e', the wires c and c being suitably connected wit-h a dynamo or other source of electricity.

I do not of course limit myself to the describedelectrical connections between the 9o wires e e' and the resistance, as said connections may be made in any suitable way.

I have found that a resistance composed Wholly or mainly of plumbago and inclosed in a refractory heat-conductin g block of soapstone operates very advantageously in heating a casing or structure in which said parts may be placed, the plumbago resistance developing a high degree of heat, which is conducted by the soapstone block to the surloo rounding casing. The plumbago resistance and soapstone block or holder possess the advantage of being extremely durable, as well as possessing the necessary qualities for the rapid generation and conduction of heat. I do not limit myself to these particular materials, however, and may use any other suitable materials.

In the speciiic form of apparatus here shown-viz., a soldering-iron-the handle f is provided With a yoke f', the arms of which bear on the exterior of the shell a, and are detachably secured to the latter by screws f2. The shell is also detachably fitted to the tubular casing b, which incloses the 'refractory block c and resistance d, so that by withdrawing the screws f2 the shell may be removed and replaced by another when it has become so reduced by wear as to be useless. The tubular casing I) is here shown as provided with an outwardly-projecting flange b at its outer end, to which is afiixed by screws or rivets b2 or otherwise a cap or cover b3, which is perforated for the passage of the wires c and e. Said cap is secured to the yokef by means of screws t' fi, passed through arms of the yoke and bearing on the flange of said cover, as shown in Figs. l and 2. Said screws 7,' constitute means for holding the tubular casing I) and its contents in engagement with the handle independently of the screwsfg, which hold the shell d, so that when said shell is removed the tubular casing b remains operatively engaged With the handle.

As already indicated, the described heating apparatus may be used for general heat# ing purposes, and is not limited toits specific application to soldering-irons.

In Fig. 4L I show a flat-iron fr, and in Fig. 5 a radiator s, provided with my improved electric-heating apparatus, said Yradiator bein g shown as provided with Wings sto atlord large areas of radiating-surface. The apparatus may also be applied to cooking-stoves.

I claim"- l. In an electric-heating apparatus,the combination, with a cylindrical inclosing shell or casing, of an inflexible block of homogeneous heat-conducting insulating material Within said shell, said block having a pocket, a rod or pencil of compressed carbon in said pocket, a plate secured to each end of the block for holding the rod in position, and electrical connections with said rod or pencil, as set forth.

2. The combination, with the casing I), of the block cof heat-conductinginsulating material, having an opening or pocket extending through it, a resistance contained in said pocket, plates c3 and 7L at the ends of the block c, means for securing them thereto, and the screws cIl and g, extending through the plates and into the block, substantially as described.

3. The combination of a resistance, a rigid holder of refractory heat-conducting insulating material, a-metallic shell inclosing said holder, a handle detaehahly secured to said shell, and an outer metallic shell detachably secured to the handle by independent means, as set forth.

In testimony whereof I have signed my nameto this specification, in the presence of two subscribing witnesses, this 13th day ot January, A. D. 1891.

ARTHUR E. APPLEYARD.

`lVitnesses:

C. F. BROWN, A. D. HARRISON. 

